A PhD student's blog about observing in Hawaii

Holiday Observing

My final observing run of the semester was on the 28 December but Santa didn’t forget to deliever the good weather! We started off with some clouds but the coverage was small and they didn’t stick around for long.

Observing Jupiter with IRTF in a few hours – currently a bit of cloud over Mauna Kea, but clear skies are forecast! pic.twitter.com/7Fw57uc00a

This time I had 6 hours of observing time and I was determined to get several complete scans of Jupiter’s aurora. As I was observing remotely from the UK, it was the civilised time of 2pm-8pm GMT. During the 6 hours I would have the opportunity to observe both the southern and northern aurora. I was excited to test iSHELL out on the southern lights, which I believe has never been done before in the H3+ wavelengths!

Originally these observations were supposed to be taken at the same time as Juno observations but since then Juno has stayed in a 53.5 day orbit and so unfortunately it was just me aurora spotting. Juno was out there somewhere in Jupiter’s magnetosphere though, and it may be the case that the measurements taken by Juno of Jupiter’s magnetic field or plasma flows will be useful in interpreting our data or vice versa.

I started off with calibrations and star spectra then settled into observing Jupiter. The southern aurora was facing Earth, so I began with observing the southern lights. I set up my macro and took a scan of the southern aurora.

Skiies are nice and clear above Mauna Kea 🙂 the sun in rising and we are moving into daytime observing… pic.twitter.com/tC8cP7EP2B

As we were observing during the day time in Hawaii, we couldn’t use an off-axis guide star to guide the telescope, which keeps the telescope accurately pointing at Jupiter. The guide-stars that IRTF use are too faint in daylight and so we couldn’t use them to guide during my daytime observations. When observing in infrared, Jupiter remains very bright in the sky even in the daytime. If Jupiter was smaller we could use the planet itself to guide but unfortunately Jupiter almost fills the field of view of the guider, so this is not a possibility. To make sure the telescope stays pointing at Jupiter the telescope operator inputs the rates at which Jupiter is known to move across the sky.

I had some trouble with the telescope drifting slightly but I managed to get several scans of Jupiter’s southern aurora. I took some random spectra of the equator too which will come in useful during the data analysis. After a couple of hours observing Jupiter southern aurora, it had almost rotated out of view and so I begin observing the northern aurora. I had some more trouble with the telescope drifting but I still got several scans of the northern aurora too.

After my allocated time had ended and I had finished shutting down the instrument, I got to join my boyfriends birthday celebrations. I heard that’s what he wanted for his birthday… lots of lovely Jupiter data!!